Translating legal and bureaucratic language into plain, comprehensible English is not amenable to simple rules and procedures. Rewriting comprehensibly requires specialized knowledge about language and an awareness of a number of misconceptions and pitfalls. This paper discusses what not to do in rewriting, based upon rewritten documents presently available to the public and upon several procedures that have been touted as panaceas. Expertise in research design and linguistic analysis is required to indirectly measure or approximate the comprehensibility of discourse. Such indirect measures include multiple choice tests, questionnaires, rating scales, and paraphrase tasks. In contrast, so-called "readability formulas," such as the Flesch Test, which don't measure comprehension or comprehensibility, have become popular. Such formulas only measure sentence length and word length but neglect logical, grammatical, and contextual criteria. Numerous examples are cited to illustrate that rigid rules cannot be made regarding the kinds of grammatical constructions that are most comprehensible. Comprehension problems can arise from a lack of contextual and pragmatic information. Difficulties in rewriting can result from relying on a thesaurus of "word frequency dictionary." Another problem that has arisen in rewriting documents, especially bank loan and insurance forms, is the trend toward personalizing these contracts, which decreases comprehensibility. (Author/SW)